Buckle

ABSTRACT

A self-locking buckle for straps, belts, bands or ties formed of a one-piece unit having two sections, one folded over the other to form a first strap connection at the juncture of folding and a second adjustable strap connection adjacent corresponding free ends of the folded unit. The latter connection is adapted to receive one end of a strap threaded over one free end of the unit and beneath the other free end reversely upon itself for longitudinal sliding adjustment of its effective length relative to the buckle and automatic locking at preselected positions of the adjustment.

Elnited States atet 1191 Schauweker et a1. June 4, 1974 [5 BUCKLE 3,414,943 12/1968 1111mm 24/200 [75] Inventors: George 1-1. Schauweker,

Southbridge; Harry Dostourian, Primary Examlf'er prancls Zugel Worcester, both of Mass Asszstant Examiner-Darrell Marquette Attorney, Agent, or Firm-H. R. Berkenstock; William [73] Assignee: American Optical Corporation, C Nealon Southbridge, Mass. [22] Filed: Nov. 3, 1972 [57] ABSTRACT [2]] Appl. No.: 303,444 A self-locking buckle for straps, belts, bands or ties formed of a one-piece unit having two sections, one folded over the other to form a first strap connection C(i1. 24/2glzi4i4/l7so at the juncture of folding and a Seqmd adjustable 58] Fie'ld 79 74 A strap connection ad acent correspond ng free ends of the folded unit. The latter connection is adapted to re- 56] References Cited ceive one end of a strap threaded over one free end of the unit and beneath the other free end reversely upon UNITED STATES PATENTS itself for longitudinal sliding adjustment of its effective 3,075,268 1/1963 Schwartz 24/200 length relative to the buckle and automatic locking at 3,206,816 9/1965 Vilcins et 211 24/200 preselected positions of the adjustment 3,214,815 11/1965 Mathison 24/200 3.315.324 4/1967 Ward 24/16 PB 3 Claims, 5 Drawing Figures BUCKLE BACKGROUND OF THE INVENTION 1. Field of the Invention Buckles for straps, belts, bands or ties and the like with particular reference to a sliding self-locking buckle.

2. Description of the Prior Art Buckles normally used for interconnecting straps, belts, headbands or ties have, heretofore, involved relatively costly and ungainly assemblies of a plurality of initially separate parts usually formed of metal. In addition to the drawback of possible mechanical failure, these buckles are usually relatively heavy in size and weight, highly absorptive to heat or cold rendering them uncomfortable to wear in certain environments and unsuitable for use in potentially explosive atmospheres requiring the wearing of completely nonmetallic nonelectrically-conductive articles of clothing and accessories. 1

Accordingly, an object of the present invention is to provide an inexpensive self-locking buckle for straps, belts, headbands or ties and the like which may be quickly and easily selectively released after locking and which is of light weight, nonelectrically conductive, inexpensive one-piece construction, relatively comfortable and safe to wear, corrosion resistant, substantially free of fouling and mechanical failure and minimally abrasive to the materials of connecting straps, belts, headbands or ties and the like.

SUMMARY OF THE INVENTION The foregoing and corrollary objects ofthe invention are accomplished through the provision of a one-piece buckle which may be molded, cast or similarly formed of a suitable dielectric plastic material such as polypropylene. The buckle is formed with a very thin, line-like cross-section extending thereacross between its opposite ends. This cross-section forms a bending line or hinge of the type commonly referred to in the art of molded plastics as a living hinge". Sections of the buckle at opposite sides of the hinge are apertured and when folded over and against each other, the buckle becomes immediately adaptable to use. In use with a strap. belt, headband or tie, one end of the strap is looped around the hinged portion of the folded buckle and secured in place while the opposite end of the strap is threaded over one of corresponding free ends of the folded buckle and reversely upon itself beneath the other free end of the buckle. The strap may then be drawn away from the buckle to a desired length adjustment. Retraction of the strap during and following such adjustment ofits length is prevented by a tightening together of the two adjacent ends of the buckle caused by the reverse threading of the strap therethrough. This self-locking effect is enhanced by serrations located beneath the second mentioned free end of the folded sections of the buckle. Release of the strap in the buckle may be effected simply and quickly by lifting the end of the buckle nearest to the serrations slightly away from the strap.

The invention will be more fully understood by reference to the following detailed description taken in conjunction with the accompanying drawings.

DESCRIPTION OF THE DRAWINGS FIG. I is a plan view of a preferred embodiment of the invention;

FIG. 2 is an end view of the buckle shown in FIG. 1;

FIG. 3 is a side elevational view of the buckle;

FIG. 4 is a plan view of the buckle illustrated in use with a strap; and

FIG. 5 is a longitudinal cross-sectional view taken along line 5-5 of FIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring more particularly to FIGS. 1-3, buckle 10 being generally rectangular as illustrated comprises a flat piece of molded plastic material such as polypropylene having a pair of openings 12 and 14 extending therethrough and separated by bridge 16.

Bridge 16 has hinge 18 comprised of a thinned-down line-like section of the material of buckle 10. This thin section is produced by forming groove 20 on one side of bridge 16 and recess 22 on its opposite side, each brought to a depth relative to the other sufficient to maintain the integrity of the bridge but with sufficient flexibility of the hinge for completely freely folding one section 24 of buckle 10 over its other section 26 as shown in FIGS. 4 and 5. These properties of mobility and flexibility, without breakdown, in thin sections of articles molded of polypropylene and similarly characterized plastic materials are well known in the art of making living hinges. Those interested in details of such hinges may refer to US. Pat. No. 3,628,215.

FIGS. 4 and 5 illustrate use'of the buckle l0. Therein it can be seen that section 24 of buckle 10, preferably being shorter than section 26, is folded about hinge 18 so as to overlie section 26 with its end rail 28. adjacent but slightly rearwardly of the corresponding 'end rail 30 of section 26.

The buckle, so folded, is attached to strap 32 by looping the strap through openings 12 and 14 around the now folded bridge 16. The free end of loop 34 is stitched, riveted, cemented or otherwise secured to the main portion of strap 32. The opposite end 35 of strap 32 is then extended up through both ,of openings 12 and 14, over rail 28 and downwardly again through opening 12, this time between rails 28 and 30, and thence outwardly beneath rail 30 reversely upon itself. Molded teeth or serrations 36 on rail 30 grip strap 32 for positive locking against slippage in the buckle when a pulling force in the direction of arrow 38 is applied. This pulling force, or a tightening of strap 32 around an object which causes the same effect, draws rail 28 downwardly toward section 26 and simultaneously forces strap 32 tightly upwardly against the bottom of rail 30. The resulting self-locking of buckle 10 can, at any time, be immediately released by lifting section 24 with a thumb and finger sufficiently to allow strap 32 to slide reversely around rail 28.

Tightening of strap 32 by pulling end 35 thereof away from buckle 10 may be accomplished simply and easily and retraction of the strap is prevented at all times by the aforementioned self-locking of the buckle until release as mentioned above, is intentionally effected.

Buckle 10 may be readily inexpensively mass produced in the flat configuration of FIGS. 1-3 of molded or cast plastic material such as polypropylene which is characteristically light in weight, nonconductive to electricity and noncorrosive to fabric, leather, plastic or other strap materials which may be used therewith. The buckle itself is essentially noncorrosive and is minimally abrasive and wearing to materials of the strap. It is resistant to overheating or the transmittance of excessive cold when worn in respectively hot or cold environments and is further distinctively automatically selflocking during and following any and all strap tightening operations.

We claim:

1. The combination of a self-locking buckle and strap, said buckle comprising a unitary main body having a pair of openings extending therethrough, a bridge separating said openings, a portion of the material of said buckle being thin and flexible in a line extending along said bridge, said line defining first and second sections of said buckle respectively at opposite sides of said bridge and said thin and flexible portion of said material constituting a hinge for folding said sections one over another when said buckle is in use, one of said sections of said buckle being folded over the other section, said strap having one of its ends looped around said bridge and its opposite end threaded completely through both of said openings in one direction thence over an outermost end of one of said sections and back through the opening in the remaining section of said buckle in a direction reversely upon itself 2. The combination according to claim 1 wherein said looped one of said strap is secured against withdrawal from said buckle.

3. The combination according to claim 2 wherein said opposite end of said strap is drawn tightly in said buckle and said outermost end of said one section of said buckle is pulled tightly against said reversely directed portion of said strap for locking said strap against retraction in said buckles 

1. The combination of a self-locking buckle and strap, said buckle comprising a unitary main body having a pair of openings extending therethrough, a bridge separating said openings, a portion of the material of said buckle being thin and flexible in a line extending along said bridge, said line defining first and second sections of said buckle respectively at opposite sides of said bridge and said thin and flexible portion of said material constituting a hinge for folding said sections one over another when said buckle is in use, one of said sections of said buckle being folded over the other section, said strap having one of its ends looped around said bridge and its opposite end threaded completely through both of said openings in one direction thence over an outermost end of one of said sections and back through the opening in the remaining section of said buckle in a direction reversely upon itself.
 2. The combination according to claim 1 wherein said looped one of said strap is secured against withdrawal from said buckle.
 3. The combination according to claim 2 wherein said opposite end of said strap is drawn tightly in said buckle and said outermost end of said one section of said buckle is pulled tightly against said reversely directed portion of said strap for locking said strap against retraction in said buckle. 